To analyze the nonlinear hysteretic behaviors of RC frame structures under reversed cyclic loading

a new element of reinforced concrete beam-column joints

super DOF element

was presented. The element edges were divided into "joint plane" and "beam-column plane" at the joint-column interface and joint-beam interface. The inelastic mechanism of joint core was represented by the four-node plane stress element. The anchorage failures of beam and column longitudinal reinforcement embedded in the joint were determined by eight springs between "joint plane" and "beam-column plane". The proposed element has four exterior nodes and four interior nodes. There are two degrees of freedom on each interior node. There are three degrees of freedom on each exterior node

coinciding with ones of typical beam element

so the element is suitable for use together with typical hysteretic beam-column line elements in two-dimensional nonlinear analysis of reinforced concrete structures. The element is implemented as a four-node twenty-degree-of-freedom element through moving the degrees of freedom on the interior nodes to ones on the exterior nodes. The simulated data were compared with tests

and the results indicate that the ultimate strengths and hysteretic pitching behaviors analyzed by the element are well agreement with the test ones and the computer time is short. It concludes that the proposed element is suitable for use in simulating response of building joints under cyclic loading.